Real-time feedback for policies for computing system management

ABSTRACT

One aspect of the invention is a method for providing real-time feedback regarding the effect of applying a policy definition used for management in a computing system. An example of the method includes receiving the policy definition, and accessing stored information regarding at least one managed entity in the computing system. This example also includes applying the policy definition to the information regarding the at least one managed entity. This example further includes outputting information providing real-time feedback regarding the effect of applying the policy definition to the information regarding the at least one managed entity. Another aspect of the invention is a method for defining a policy used for management in a computing system.

BACKGROUND

1. Technical Field

The present invention relates to management and control of resources ina computing system. More particularly, the invention concerns defining apolicy, or providing real-time feedback regarding the effect of applyinga policy used for management in a computing system.

2. Description of Related Art

Modern computing systems frequently include a large number of computingdevices, storage devices, and other components. Management programs maybe used to manage these computing environments. Some management productsoffer policy-based schemes for managing different entities in computingsystems, such as security settings for a large user base, or storageresources throughout an enterprise. The policies may be, for example,simple rules, or complex, hierarchical, inheritance policies.

Storage resource manager (SRM) software is often used to manage entitiesin computing systems. For example, IBM Tivoli Storage Resource Manager(ITSRM) may be used to manage storage resources. SRM softwarefacilitates management of storage resources throughout an enterprise bycentrally monitoring storage assets and their utilization, by reportingevents, and by allocating storage based on pre-defined policies. As anexample, a SRM may provide automatic, policy-based provisioning ofstorage resources for host computer systems in an enterprise in order tosatisfy criteria for each machine such as free space or capacity.

Although policy-based products are widely used, they are often difficultto use to their full advantage because they do not provide a “preview”to show an administrator the effect that potential new or changedpolicies will have upon the entities managed by those policies. Becauseof this limitation, it is difficult for a policy administrator toconduct various “what-if” scenarios that may be necessary forimplementing a successful policy. Due to the absence of real-timefeedback, administrators are forced to either attempt to manually runthrough all of the possible scenarios, or to follow a “try-it-and-see”method where they implement a “best guess” policy and test it out to seewhat it actually does. Such approaches to managing policies are oftenlabor intensive, error-prone, and unpredictable.

SUMMARY

One aspect of the invention is a method for providing real-time feedbackregarding the effect of applying a policy definition used for managementin a computing system. An example of the method includes receiving thepolicy definition, and accessing stored information regarding at leastone managed entity in the computing system. This example also includesapplying the policy definition to the information regarding the at leastone managed entity. This example further includes outputting informationproviding real-time feedback regarding the effect of applying the policydefinition to the information regarding the at least one managed entity.Another aspect of the invention is a method for defining a policy usedfor management in a computing system.

Other aspects of the invention are described in the sections below, andinclude, for example, a computing system, and a signal bearing mediumtangibly embodying a program of machine-readable instructions executableby a digital processing apparatus to perform a method for providingreal-time feedback regarding the effect of applying a policy definitionused for management in a computing system, or to perform a method fordefining a policy used for management in a computing system.

Some examples of the invention provide one or more of the followingadvantages: Real-time feedback is provided concerning the effect of anew or changed policy. The effects of policy changes are predictedbefore changes are implemented. Manual effort required to assess effectsof policies is significantly reduced, and the possibility of human erroris also reduced. Other examples of the invention have the ability todefine policies to achieve specified overall results. Some examples ofthe invention also provide a number of other advantages and benefits,which should be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of the hardware components andinterconnections of a computing system in accordance with an example ofthe invention.

FIG. 2 is an example of a signal-bearing medium in accordance with anexample of the invention.

FIG. 3 is a flowchart of an operational sequence for providing real-timefeedback regarding the effect of applying a policy definition used formanagement in a computing system, in accordance with an example of theinvention.

FIGS. 4A-B are a flowchart of an operational sequence for defining apolicy used for management in a computing system, in accordance with anexample of the invention.

FIG. 5 provides a Graphical Unser Interface indicating managed entitiesaffected by policy definitions.

FIG. 6 illustrates information used by a sequence to apply a prospectivepolicy definition to managed entities.

DETAILED DESCRIPTION

The nature, objectives, and advantages of the invention will become moreapparent to those skilled in the art after considering the followingdetailed description in connection with the accompanying drawings.

I. Hardware Components and Interconnections

One aspect of the invention is a computing system that can be used forproviding real-time feedback regarding the effect of applying a policydefinition used for management in a computing system, and for defining apolicy used for management in a computing system. As an example, thecomputing system may be embodied by all, or portions of, the computingsystem 100 shown in FIG. 1. However, examples of the invention could beimplemented on computing systems having different components than thecomputing system 100. The computing system 100 includes a first host 102and a second host 104. Alternatively, only one host could be included,or additional hosts could be included, and client computers could beincluded. The computing system 100 also includes an ITSRM server 106,and a CIM Server 107 (which may also be called a CIM Object Manager(CIMOM)). A CIM Server is a server that runs a common interface formanaging a storage system. Each host 102, 104, ITSRM server 106, and theCIM server 107 may run the same or different operating systems, whichcould be any suitable operating system(s), for example, WINDOWS 2000,AIX, Solaris™, Linux, UNIX, or HP-UX™. Each host 102, 104, ITSRM server106, and the CIM server 107 may be implemented with any suitablecomputing device, and may be implemented with the same, or differentcomputing devices. As an example, host 102, host 104, ITSRM server 106,and the CIM server 107 could be a personal computer (having for example,an Intel processor running the WINDOWS or Linux operating system), acomputer workstation, a mainframe computer, a supercomputer (for examplean IBM SP2 running the AIX operating system), or any other suitablecomputing device running any suitable operating system. In otherexamples, the host 102, host 104, ITSRM server 106, and the CIM server107 could be an IBM xSeries server, or an IBM zSeries Parallel Sysplexserver, such as a zSeries 900, running the z Operating System (z/OS), oran IBM S/390 server running OS/390. Some examples of the invention maybe incorporated into IBM Tivoli Storage Resource Manager (ITSRM) 1.2,and may supplement the “Automatic policy-based filesystem extension”feature. The hosts 102, 104, ITSRM server 106, and the CIM server 107may be coupled to each other with a network 108, which may be an IPnetwork, and which could be any suitable type of network, for example,Ethernet, ESCON (Enterprise Systems CONnnector), or FICON (FIberCONnector). Additionally, network 108 could use the Internet, and couldutilize wireless technology. The hosts 102, 104 need not be coupled tothe CIM server 107 via the network 108.

The host 102 has a processor 110 (which may be called a processingdevice), and in some examples could have more than one processor. As anexample, the processor 110, may be a PowerPC RISC processor or an IBMP690 power 4 processor, available from International Business MachinesCorporation. In another example, the processor 110 could be a processormanufactured by Intel Corporation. The host 102 also may have a memorysubsystem that may include a primary memory 112 (for example RAM),and/or a non-volatile memory 114, both of which are coupled to theprocessor 110. The memory subsystem may be used to store data andapplication programs and/or other programming instructions executed bythe processor 110. The application programs could generally be anysuitable applications. In some examples, embodiments of the methodaspects of the invention could run on the host 102. The non-volatilememory 114 could be, for example, a hard disk drive, a drive for readingand writing from optical or magneto-optical media, a tape drive,non-volatile RAM (NVRAM), or any other suitable type of storage. In someexamples the primary memory 112 or the non-volatile memory 114 could beeliminated, or the primary memory 112 and/or the non-volatile memory 114could be provided on the processor 110, or alternatively, external fromthe host 102. The host 102 also has a hardware bus adapter (HBA) 116,coupled to the processor 110, for coupling the host 102 via connector156 a to a Fibre Channel network (which may be called a “fabric) thatmay be used to implement a SAN 118. As an example, connector 156 a maysupport FICON (FIber CONnector), ESCON (Enterprise Systems CONnnector)communications channels. As an example, the hardware bus adapter 116could be a model 2200 hardware bus adapter available from QLogicCorporation. Generally, the SAN 118 may be implemented using FibreChannel network(s) and/or Ethernet network(s). In other embodiments aSAN need not be included. Using the SAN 118 permits coupling a largenumber of storage devices to the hosts 102, 104.

Similar to host 102, host 104 has a processor 120, a memory subsystemthat that may include a primary memory 122 (for example RAM), and/or anon-volatile memory 124, both of which are coupled to the processor 120.The memory subsystem may be used to store data and application programsand/or other programming instructions executed by the processor 120. Theapplication programs could generally be any suitable applications. Insome examples, embodiments of the method aspects of the invention couldrun on the host 104. The host 104 also has a hardware bus adapter 126,for coupling the host 104 to the SAN 118 via connector 156 b.

Similar to hosts 102 and 104, ITSRM server 106 has a processor 130, amemory subsystem that may include a primary memory 132 (for exampleRAM), and/or a non-volatile memory 134, both of which are coupled to theprocessor 130. The memory subsystem may be used to store data andapplication programs and/or other programming instructions executed bythe processor 130. The application programs could generally be ITSRM andany other suitable applications. In some examples, embodiments of themethod aspects of the invention could run on the ITSRM server 106. Insome examples the ITSRM server 106 could have a hardware bus adapter(not shown) and could be coupled to the SAN 118. In some embodiments,the ITSRM server 106 is not included in the computing system 100.

Similar to hosts 102 and 104, and ITSRM server 106, CIM server 107 has aprocessor 140, a memory subsystem that may include a primary memory 142(for example RAM), and/or a non-volatile memory 144, both of which arecoupled to the processor 140. The memory subsystem may be used to storedata and application programs and/or other programming instructionsexecuted by the processor 140. The application programs could generallybe a CIM Object Manager program, and any other suitable applications. Insome examples, embodiments of the method aspects of the invention couldrun on the CIM server 107. In some examples, the CIM server 107 couldhave a hardware bus adapter (not shown) and could be coupled to the SAN118. In alternative embodiments, the CIM Server 107 could be embedded inother devices, such as, for example, a storage system 148 or storagesystem 149 discussed below. In some embodiments, the CIM server 107 isnot included in the computing system 100. Also, in some embodiments, theCIM server 107 could be embedded in a storage system.

The computing system 100 also may include storage system 148 and storagesystem 149. Storage devices 150 a-b are included in storage system 148,and storage devices 150 c-d are included in storage system 149. Thestorage systems 148, 149 could include additional storage devices.Generally, a large number of storage systems may be coupled to the SAN118. Storage devices that are not in storage systems could be coupleddirectly to the SAN 118, or could be coupled to the SAN 118 through aswitch (not shown). The storage devices 150 a-d are coupled to hosts102, 104 through the SAN 118, via connectors 156 a-d. As an example,connectors 156 a-d could support FICON (FIber CONnector) or ESCON(Enterprise Systems CONnnector) communications channels. However, othertypes of connections could be used. Each storage system 148, 149 has astorage controller (not shown) and is coupled to the SAN 118 through anetwork adapter (not shown). There may be multiple paths to the storagesystems 148, 149 in the SAN 118. In alternative embodiments, computingenvironments that include storage systems but that do not include a SANcould be used. The CIM server 107 is coupled to the storage systems 148,149 via the network 158, which may be an IP network, and which could beany suitable type of network, for example, Ethernet, ESCON (EnterpriseSystems CONnnector), or FICON (FIber CONnector). Additionally, network158 could use the Internet, and could utilize wireless technology.

The plurality of storage devices 150 a-d may include, for example, harddrives. However, each of the storage devices in the plurality of storagedevices could be implemented with any suitable type of storage device,using any suitable technology, such as magnetic, optical,magneto-optical, or electrical. For example, suitable storage devicescould include hard disk drives, optical disks or discs (for example,CD-RW, DVD-RW, or DVD+RW), floppy disks, magnetic data storage disks ordiskettes, magnetic tape, digital optical tape, a tape library, EPROMs,EEPROMs, RAM, Non-Volatile RAM, and flash memory. Additionally, CD-R,WORM, DVD-R, and/or DVD+R devices could be included in the pluralitystorage devices. As an example, one or more of the storage systems 148,149 could be implemented with a Model F20 or Model 800 EnterpriseStorage Server, available from IBM Corporation. As another example, diskstorage could be implemented with an IBM FAStT 900, and a tape librarycould be implemented with an IBM 3494 tape library using IBM 3590drives, all of which are available from IBM Corporation.

II. Operation

In addition to the hardware embodiments described above, other aspectsof the invention concern methods for providing real-time feedbackregarding the effect of applying a policy definition used for managementin a computing system, and for defining a policy used for management ina computing system.

A. Signal-Bearing Media

In the context of FIG. 1, the method aspects of the invention may beimplemented, for example, by having the host 102, the host 104, theITSRM Server 106, and/or the CIM server 107 execute a sequence ofmachine-readable instructions, which can also be referred to as code.These instructions may reside in various types of signal-bearing media.In this respect, some aspects of the present invention concern aprogrammed product, comprising a signal-bearing medium or signal-bearingmedia tangibly embodying a program of machine-readable instructionsexecutable by a digital processing apparatus to perform a method forproviding real-time feedback regarding the effect of applying a policydefinition used for management in a computing system, or to perform amethod for defining a policy used for management in a computing system.

This signal-bearing medium may comprise, for example, primary memory 112and/or non-volatile memory 114, primary memory 122 and/or non-volatilememory 124, primary memory 132 and/or non-volatile memory 134, and/orprimary memory 142 and/or non-volatile memory 144. Alternatively, theinstructions may be embodied in a signal-bearing medium such as theoptical data storage disc 200 shown in FIG. 2. The optical disc can beany type of signal bearing disc or disk, for example, a CD-ROM, CD-R,CD-RW, WORM, DVD-R, DVD+R, DVD-RW, or DVD+RW. Additionally, whethercontained in the computing system 100, or elsewhere, the instructionsmay be stored on any of a variety of machine-readable data storagemediums or media, which may include, for example, a “hard drive”, a RAIDarray, a RAMAC, a magnetic data storage diskette (such as a floppydisk), magnetic tape, digital optical tape, RAM, ROM, EPROM, EEPROM,flash memory, magneto-optical storage, paper punch cards, or any othersuitable signal-bearing media including transmission media such asdigital and/or analog communications links, which may be electrical,optical, and/or wireless. As an example, the machine-readableinstructions may comprise software object code, compiled from a languagesuch as “C++”, or may comprise Java bytecode.

B. Overall Sequence of Operation

For ease of explanation, but without any intended limitation, the methodaspects of the invention are described with reference to the computingsystem 100 described above and shown in FIG. 1.

FIRST EXAMPLE OF METHOD ASPECT OF THE INVENTION

A first example of the method aspect of the present invention isillustrated in FIG. 3, which shows a sequence 300 for a method forproviding real-time feedback regarding the effect of applying a policydefinition used for management in a computing system. The sequence 300could be performed by host 102, host 104, ITSRM server 106, CIM server107, or by some other computing device. Referring to FIG. 3, thesequence 300 may include, and begin with, operation 302 which comprisesstoring historical information regarding the at least one managed entityin an information repository. As an example, the information may begathered by an agent on a host 102, 104, and may be sent to the ITSRMserver 106 for storage. As an example, the information may includeattributes regarding managed entities, such as the amount of space in afilesystem, and how much space is in use in the filesystem. As anexample, the information repository could be a data base, which could bemaintained by the ITSRM server 106. However, the data base could belocated elsewhere in the computing system 100. As an example, the atleast one managed entity may include a storage device entity. As anotherexample, the at least one managed entity may include a memory entity. Asanother example, the at least one managed entity may include a CPU(Central Processing Unit) entity. Herein CPU means a processor having acontrol unit and an arithmetic logic unit.

Sequence 300 may also include operation 304, which comprises receiving apolicy definition. A policy may also be called a rule. A policydefinition may include a list of one or more managed entities to whichthe policy definition is to be applied (which may be called the“binding”). The policy definition may be a new policy definition, amodification of a previous policy definition, or may include informationindicating that a policy definition is to be applied to a differententity to which it was not previously applied. The policy definition maybe stored on the ITSRM server 106, or elsewhere in the computing system100. As an example, the policy definition may pertain to storageresource management in the computing system 100. As another example, thepolicy definition may pertain to automatic policy-based filesystemextension in the computing system 100. As another example, the policydefinition may pertain to security in the computing system 100. In aspecific example relating to tape storage systems, the policy definitioncould specify that a reclaim operation should be performed for a tapestorage system if unused space exceeds 60%. An administrator couldchange the policy definition to specify that the reclaim operationshould be performed if unused space exceeds 40%, and could use someexamples of the invention to compare the effects of this policydefinition with the effects of the policy definition with the 60%threshold. An example of a policy definition, relating to hard drivereplacement, could state that a hard drive should be replaced if thenumber of detected errors is greater than a specified number. An exampleof a policy definition relating to email management, could state that ifa user is using more than 100 Mbytes of storage for email, then the userwill be required to delete some email files or will be charged asurcharge. Policies relating to email management could also be based onthe daily volume of email, or the age of email files.

Sequence 300 may also include operation 306, which comprises accessingstored information regarding at least one managed entity in thecomputing system. The information that is accessed in operation 306 issome or all of the information stored in operation 302. Sequence 300 mayalso include operation 308, which comprises applying the policydefinition to the information regarding the at least one managed entity.The policy definition will generally be applied to data regardingattributes of managed entities that is included in the storedinformation. Examples of attributes for filesystem entities include theamount of free space, and how much space in the filesystem is in use. Ifdesired, the effect of the policy definition may be evaluated withregard to all of the managed entities. The policy definition or asimilar policy definition may have previously been applied to the atleast one managed entity. In some examples the applying operation maycomprise applying the policy definition to a managed entity to which thepolicy definition or a similar policy definition has not previously beenapplied.

Sequence 300 may also include operation 310, which comprises outputtinginformation providing real-time feedback regarding the effect ofapplying the policy definition to the information regarding the at leastone managed entity. The “effect” may include plural effects if there ismore than one effect. As an example, if an entity with known attributesis assigned to be managed by a different policy, the effects of thepolicy change can be previewed or immediately evaluated once the changeis made. In some examples the policy definition has not been implemented(also called committed), when the information providing real-timefeedback is outputted, and this may be called a preview mode.Alternatively, in some examples the information providing real-timefeedback is outputted substantially immediately after implementation ofthe policy. As an example, the information providing real-time feedbackmay be outputted within 10 seconds from when the policy definition isreceived. In other examples the information providing real-time feedbackcould be outputted within one minute, within 30 seconds, within 5seconds, or within 1 second, from when the policy definition isreceived.

The operation of outputting information providing real-time feedback maycomprise outputting the information from a software module or from acomputing system, or may further comprise displaying information on aGUI (Graphical User Interface) 500 (FIG. 5) indicating which managedentities in a plurality of managed entities would be affected if thepolicy definition were to be implemented. More specifically, theoperation of outputting information providing real-time feedback maycomprise displaying information on a GUI 500 indicating host machinesand filesystems that would be affected if the policy definition were tobe implemented. For example, a file tree 502 could be displayed, whereinfilesystems that will be immediately affected by a policy definition arehighlighted. This feedback can help an administrator determine whichfilesystems a policy should be tailored to apply to. After receivingfeedback for a policy definition, operations 304, 306, 308, and 310could be repeated with another policy definition supplied by theadministrator, and the administrator could compare the effects of thedifferent policies.

Thus, some embodiments of the invention provide real-time feedback topolicy administrators, permitting policy administrators to see what theeffects of policy decisions will be before implementing a policy. Thereal-time feedback can be used to help an administrator determine whatpolicies to set, and to permit the administrator to anticipate theeffects of those policies (for example, which managed entities will beaffected, and to what degree the entities will be affected). While thismethod of real-time feedback is applicable to many fields, someexemplary applications include system management and storage resourcemanagement, and a specific application is automated filesystemextension. In the automated filesystem extension application, anadministrator can create policies to determine when a filesystem shouldbe extended. For example, a policy could be created that provides, “whenthe filesystems on monitored host machines reach 80% of their maximumcapacity, extend those filesystems so that they have 50% free space.”While this policy is relatively easy to understand and seems useful, itmay be a dangerous policy to implement. For example, it is possible thatthis policy will affect filesystems that the administrator had notintended to modify (such as root filesystems) because it is so broad inscope. It is also possible that several of the monitored filesystems arealready at 80% of their maximum capacity. In this latter case,implementing the policy immediately might result in several filesystemsbeing extended at once and there might not be sufficient availablestorage in a computing network to accommodate the sudden growth. To helpthe administrator better understand the consequences of policy choices,some examples of the invention can be used to simulate use of a policyand to notify the administrator as to exactly which managed entitieswill be affected by policy changes. Specifically, when a policydefinition is modified in any way (for example, a new filesystem isassociated with a policy), the backend of a system implementing anexample of the invention could immediately compare that policy againstthe information it has already collected about the entity to which thatpolicy will be applied (in this case, the new filesystem), to determinethe effect of the change (for example, will this filesystem need to beextended). This method allows the GUI to immediately show theadministrator which host machines and filesystems would be affected byproposed policy settings without the administrator having to actuallyimplement that policy and without waiting for any sort of discoveryaction (for example, without having to wait several hours to see whathappens after the policy is implemented).

SECOND EXAMPLE OF METHOD ASPECT OF THE INVENTION

A second example of the method aspect of the present invention isillustrated in FIGS. 4A-B, which show a sequence 400 for a method fordefining a policy used for management in a computing system. Thesequence 400 could be performed by host 102, host 104, ITSRM server 106,CIM server 107, or by some other computing device. Referring to FIG. 4A,the sequence 400 may include, and begin with, operation 402 whichcomprises storing information in an information repository regarding theat least one managed entity. As an example, the information repositorycould be a data base, and could be in the ITSRM server 106. As anexample, the information may indicate the amount of space in afilesystem, and how much space in the filesystem is in use. As anexample, the at least one managed entity may include a storage deviceentity (and in this case, as an example, policies could relate torequesting a filesystem extension). As another example, the at least onemanaged entity could include a memory entity (and in this case, policiescould relate to memory allocation). As another example, the at least onemanaged entity could include a CPU entity (and in this case, policiescould relate to allocation of CPU cycles to various tasks so as tooptimize desired performance characteristics).

Sequence 400 may also include operation 404, which comprises receiving aspecified result. For example, an administrator could specify the resultthat a system allocate available storage space to filesystems in anenterprise so as to maximize min_pct_free_space (the smallest percentageof free-space of any filesystem in the enterprise). An example of theinvention could then be used to determine a policy for maximizingmin_pct_free_space.

Sequence 400 may also include operation 406, which comprises receiving adefinition of a prospective policy 552 (FIG. 6), in a computing system550, and a list of policy parameters 554 (also called criteria) that maybe adjusted. The list 554 may include one or more parameters, and mayalso include information prioritizing the parameters 556 in a particularorder, and may also include information indicating a range for eachparameter 558. For example, the prioritizing information 556 mayindicate that a first parameter may be varied within a first range toattempt to produce the specified result, and that a second parameter maybe varied within a second range to attempt to produce the specifiedresult. The second parameter may be varied to attempt to produce thespecified result if the specified result cannot be produced by varyingthe first parameter within the first range, or if more than onesuccessful policy is desired. Also, more than two parameters may beprioritized, and varied to attempt to achieve the specified result. Asan example, the policy may pertain to automatic policy based filesystemextension in a computing system. Policy parameters may include, forexample, the threshold percentage of filesystem usage that will triggera request for a filesystem extension. In a hard drive replacementapplication, policy parameters may include the number of errors thatwill trigger a recommendation of replacement of a hard drive. Sequence400 may also include operation 408, which comprises accessing storedinformation regarding at least one managed entity in the computingsystem. Sequence 400 may also include operation 410, which comprisesapplying the definition of the prospective policy to the informationregarding the at least one managed entity.

Referring to FIG. 4B, sequence 400 may also include operation 412, whichcomprises determining if the result of applying the definition of theprospective policy to the information regarding the at least one managedentity achieves the specified result. Sequence 400 may also includeoperation 413, which comprises determining if multiple policies thatachieve the specified result (successful policies) are desired. If it isdetermined in operation 412 that the result of applying the definitionof the prospective policy to the information regarding the at least onemanaged entity achieves the specified result, and if it is determined inoperation 413 that multiple policies are not desired, then sequence 400may include operation 414, which comprises outputting the policy (alsocalled the policy definition). In some examples outputting operation 414may be performed even if it is determined in operation 413 that multiplepolicies are desired. As an example, outputting the policy could includeoutputting the policy from a software module or from a computing system,and could also include displaying the policy on a GUI. The operation 414of outputting the policy may also include outputting informationindicating what action will be taken if the outputted policy isimplemented.

If in operation 412 it is determined that the result of applying thedefinition of the prospective policy to the information regarding the atleast one managed entity does not achieve the specified result, or if itis determined in operation 413 that multiple policies are desired, thenthe sequence 400 may include one or more of the operations 416, 418,420, 421, and 422. Operation 416 comprises varying a parameter of theprospective policy to create a modified prospective policy definition(also called a modified prospective policy). Operation 418 comprisesapplying the modified prospective policy definition to the informationregarding the at least one managed entity. Operation 420 comprisesdetermining if the result of applying the modified prospective policydefinition to the information regarding the at least one managed entityachieves the specified result. If in operation 420 it is determined thatthe result of applying the definition of the modified prospective policyto the information regarding the at least one managed entity does notachieve the specified result, then one or more of operations 416, 418,and 420 may be repeated. Sequence 400 may also include operation 421,which comprises determining if additional successful policies aredesired. Operation 421 may be performed if in operation 420 it isdetermined that the result of applying the definition of the modifiedprospective policy to the information regarding the at least one managedentity achieves the specified result. If in operation 421 it isdetermined that additional successful policies are desired, operations416, 418 and 420 may be repeated. If it is determined in operation 421that additional successful policies are not desired, then outputtingoperation 422 may be performed. Consequently, a policy and/or one ormore modified policies may be identified that achieve the specifiedresult, and the successful policy and/or the one or more successfulmodified policies may be outputted in operation 422. In this case theadministrator may choose which outputted policy definition or modifiedpolicy definition to implement.

Thus, with the second example of the method aspect of the invention, anadministrator describes a desired overall result, and employs an exampleof the invention to define a policy that achieves the desired result.

III. Other Embodiments

While the foregoing disclosure shows a number of illustrativeembodiments of the invention, it will be apparent to those skilled inthe art that various changes and modifications can be made hereinwithout departing from the scope of the invention as defined by theappended claims. Furthermore, although elements of the invention may bedescribed or claimed in the singular, the plural is contemplated unlesslimitation to the singular is explicitly stated.

1. A method for providing real-time feedback regarding the effect ofapplying a policy definition used for management in a computing system,wherein the method comprises the following operations: receiving apolicy definition; accessing stored information regarding managedentities in the computing system, wherein the information includes forthe managed entities attributes of resources maintained by the managedentities, and wherein the policy definition specifies at least oneoperation to perform based on a condition with respect to at least oneof the attributes of at least one of the resources maintained by atleast one of the managed entities; applying the policy definition to theinformation regarding the managed entities to determine whether theattributes of the resources of the managed entities satisfy thecondition of the policy definition; providing real-time feedbackregarding the effect of applying the policy definition to theinformation regarding the managed entities, wherein the effect for themanaged entities comprises results of performing the at least oneoperation with respect to the managed entities whose attribute of theresource satisfies the condition of the policy definition; anddisplaying, as part of providing the real-time feedback, information ona GUI indicating host machines and filesystems that will be affected ifthe policy definition is implemented, and displaying a file tree on theGUI wherein resources of the managed entities affected by the policydefinition are highlighted.
 2. The method of claim 1: wherein the policydefinition specifies that a reclaim operation should be performed for atape storage system if unused space exceeds 40%; and wherein theoperations further comprise: repeating the operations of receiving thepolicy definition, accessing the stored information, applying the policydefinition, providing the real-time feedback, and displaying informationon the GUI, wherein the policy definition specifies that a reclaimoperation should be performed for a tape storage system if unused spaceexceeds 60%; and comparing the effects of the policy definition thatspecifies that a reclaim operation should be performed for a tapestorage system if unused space exceeds 40% with the policy definitionthat specifies that a reclaim operation should be performed for a tapestorage system if unused space exceeds 60%.
 3. The method of claim 1,wherein the policy definition comprises at least one of: a new policydefinition; a modification of a previous policy definition; for storageresource management in the computing system; for automatic policy-basedfilesystem extension in the computing system; and for security in thecomputing system.
 4. The method of claim 1, wherein the method furthercomprises storing information regarding the managed entities in aninformation repository.
 5. The method of claim 1, wherein the applyingoperation comprises applying the policy definition to a managed entityto which the policy definition has not previously been applied.
 6. Themethod of claim 1, wherein the policy definition has not beenimplemented when the information providing real-time feedback isoutputted.
 7. The method of claim 1, wherein the information providingrealtime feedback is outputted substantially immediately afterimplementation of the policy.
 8. The method of claim 1, wherein theinformation providing real-time feedback is outputted within 10 secondsfrom when the policy definition is received.
 9. The method of claim 1,wherein the displayed information includes information indicating whataction will be taken if the policy definition is implemented.
 10. Themethod of claim 1, wherein the information providing real-time feedbackis outputted within 1 second from when the policy definition isreceived.
 11. The method of claim 1, wherein the information regardingat least one of the managed entities in the computing system indicatesthe amount of space in a filesystem, and how much of the space is inuse.
 12. The method of claim 1, wherein at least one of the managedentities comprises at least one of: a storage device entity; a memoryentity; a CPU entity.
 13. A computing system, comprising: a memory; anda processing device coupled to the device, wherein the processing deviceis programmed to perform operations for providing real-time feedbackregarding the effect of applying a policy definition used for managementin the computing system, the operations comprising: receiving a policydefinition; accessing stored information regarding managed entities inthe computing system, wherein the information includes for the managedentities attributes of resources maintained by the managed entities, andwherein the policy definition specifies at least one operation toperform based on a condition with respect to at least one of theattributes of at least one of the resources maintained by at least oneof the managed entities; applying the policy definition to theinformation regarding the managed entities to determine whether theattributes of the resources of the managed entities satisfy thecondition of the policy definition; providing real-time feedbackregarding the effect of applying the policy definition to theinformation regarding the managed entities, wherein the effect for themanaged entities comprises results of performing the at least oneoperation with respect to the managed entities whose attribute of theresource satisfies the condition of the policy definition; anddisplaying, as part of providing the real-time feedback, information ona GUI indicating host machines and filesystems that will be affected ifthe policy definition is implemented, and displaying a file tree on theGUI wherein resources of the managed entities affected by the policydefinition are highlighted.
 14. The computing system of claim 13:wherein the policy definition specifies that a reclaim operation shouldbe performed for a tape storage system if unused space exceeds 40%; andwherein the operations farther comprise: repeating the operations ofreceiving the policy definition, accessing the stored information,applying the policy definition, providing the real-time feedback, anddisplaying information on the GUI, wherein the policy definitionspecifies that a reclaim operation should be performed for a tapestorage system if unused space exceeds 60%; and comparing the effects ofthe policy definition that specifies that a reclaim operation should beperformed for a tape storage system if unused space exceeds 40% with thepolicy definition that specifies that a reclaim operation should beperformed for a tape storage system if unused space exceeds 60%.
 15. Thecomputing system of claim 13, wherein the policy definition comprises atleast one of: a new policy definition; a modification of a previouspolicy definition; for storage resource management in the computingsystem; for automatic policy-based filesystem extension in the computingsystem; and for security in the computing system.
 16. The computingsystem of claim 13, wherein the method further comprises storinginformation regarding the managed entities in an information repository.17. The computing system of claim 13, wherein the applying operationcomprises applying the policy definition to a managed entity to whichthe policy definition has not previously been applied.
 18. The computingsystem of claim 13, wherein the policy definition has not beenimplemented when the information providing real-time feedback isoutputted.
 19. The computing system of claim 13, wherein the informationproviding realtime feedback is outputted substantially immediately afterimplementation of the policy.
 20. The computing system of claim 13,wherein the displayed information includes information indicating whataction will be taken if the policy definition is implemented.
 21. Thecomputing system of claim 13, wherein the information regarding at leastone of the managed entities in the computing system indicates the amountof space in a filesystem, and how much of the space is in use.
 22. Thecomputing system of claim 13, wherein at least one of the managedentities comprises at least one of: a storage device entity; a memoryentity; a CPU entity.
 23. A machine readable data storage mediumtangibly embodying a program of machine-readable instructions executableby a digital processing apparatus for providing real-time feedbackregarding the effect of applying a policy definition used for managementin a computing system, the operations comprising: receiving a policydefinition; accessing stored information regarding managed entities inthe computing system, wherein the information includes for the managedentities attributes of resources maintained by the managed entities, andwherein the policy definition specifies at least one operation toperform based on a condition with respect to at least one of theattributes attribute of at least one of the resources maintained by atleast one of the managed entities; applying the policy definition to theinformation regarding the managed entities to determine whether theattributes of the resources of the managed entities satisfy thecondition of the policy definition; providing real-time feedbackregarding the effect of applying the policy definition to theinformation regarding the managed entities, wherein the effect for themanaged entities comprises results of performing the at least oneoperation with respect to the managed entities whose attribute of theresource satisfies the condition of the policy definition; displaying,as part of providing the real-time feedback, information on a GUIindicating host machines and filesystems that will be affected if thepolicy definition is implemented, and displaying a file tree on the GUIwherein resources of the managed entities affected by the policydefinition are highlighted.
 24. The machine readable data storage mediumof claim 23: wherein the policy definition specifies that a reclaimoperation should be performed for a tape storage system if unused spaceexceeds 40%; and wherein the operations further comprise: repeating theoperations of receiving the policy definition, accessing the storedinformation, applying the policy definition, providing the real-timefeedback, and displaying information on the GUI, wherein the policydefinition specifies that a reclaim operation should be performed for atape storage system if unused space exceeds 60% ; and comparing theeffects of the policy definition that specifies that a reclaim operationshould be performed for a tape storage system if unused space exceeds40% with the policy definition that specifies that a reclaim operationshould be performed for a tape storage system if unused space exceeds60%.
 25. The machine readable data storage medium of claim 23, whereinthe policy definition comprises at least one of: a new policydefinition; a modification of a previous policy definition; for storageresource management in the computing system; for automatic policy-basedfilesystem extension in the computing system; and for security in thecomputing system.
 26. The machine readable data storage medium of claim23, wherein the method further comprises storing information regardingthe managed entities in an information repository.
 27. The machinereadable data storage medium of claim 23, wherein the applying operationcomprises applying the policy definition to a managed entity to whichthe policy definition has not previously been applied.
 28. The machinereadable data storage medium of claim 23, wherein the policy definitionhas not been implemented when the information providing real-timefeedback is outputted.
 29. The machine readable data storage medium ofclaim 23, wherein the information providing realtime feedback isoutputted substantially immediately after implementation of the policy.30. The machine readable data storage medium of claim 23, wherein thedisplayed information includes information indicating what action willbe taken if the policy definition is implemented.
 31. The machinereadable data storage medium of claim 23, wherein the informationregarding at least one of the managed entities in the computing systemindicates the amount of space in a filesystem, and how much of the spaceis in use.
 32. The machine readable data storage medium of claim 23,wherein at least one of the managed entities comprises at least one of:a storage device entity; a memory entity; a CPU entity.